Rancho Rinconada, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

489
FXUS66 KMTR 272048
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
148 PM PDT Sun Apr 27 2025

...New SYNOPSIS, SHORT TERM, LONG TERM...

.SYNOPSIS...
Issued at 144 PM PDT Sun Apr 27 2025

Shower chances are diminishing across the Bay Area and Central
Coast through the remainder of today. Drier, warmer conditions are
expected Monday through late next week when unsettled weather
returns again.

&&

.SHORT TERM...
(This evening through Monday)
Issued at 144 PM PDT Sun Apr 27 2025

Light showers persist across the southern half of the Bay Area and
Central Coast through early this afternoon. Showers overperformed
along the Central Coast in part due to orographic lifting and in
part due to a lingering moist air mass. Enough moisture lingered in
the wake of yesterday`s low pressure system that light rain showers
were able to continue across the Bay Area and Central Coast today.
The 12Z (5AM) sounding observed a PWAT value of 0.84 inches at OAK
this morning with the daily 12Z mean PWAT value being only 0.78
inches. While only slightly higher than the mean, this was still
more than enough moisture to support continued light rain
development this morning. Shower chances decrease this afternoon
as our moist air mass continues to progress eastward with the
upper level trough and a drier air mass arrives. Notably we will
see drier air advected into the mid and upper levels of the
atmosphere with mid and high level cloud cover expected to
dissipate tonight. Surface conditions, however, look to remain
slightly more moist with drier surface air staying offshore. Moist
conditions in the lower levels and light winds overnight will
result in a high likelihood of fog development tonight along the
coast and across the interior valleys. Fog and low clouds will
likely linger into the early morning commute tomorrow so for those
early morning commuters remember to slow down if you encounter
fog and watch for sudden changes in visibility.

High temperatures across the interior will be in the low to mid 60s
while high temperatures along the coast will largely be in the 50s
today. Tired of below seasonal temperatures? The pattern is set to
change beginning Monday with temperatures warming, becoming more
seasonal, into the upper 60s to low 70s across the interior and
upper 50s to 60s along the coast. Some potential for light offshore
winds on Monday as the trough deepens, becoming more positively
tilted over the Four Corners region. This will result in developing
upper level ridging taking a slightly positive tilt over the West
Coast on Monday before switching to zonal (horizontal) flow Monday
into Tuesday. This will shift our surface winds to be out of a more
N to NE direction (offshore) but winds should remain light due to
persisting high pressure at the surface. Locally breezy conditions
may develop across the higher elevations with gusts up to 25 mph
possible.

&&

.LONG TERM...
(Monday night through next Saturday)
Issued at 144 PM PDT Sun Apr 27 2025

Surface high pressure and upper level ridging will generally persist
through late next week. Temperatures will continue to warm
Tuesday/Wednesday with seasonal highs in the mid to upper 70s across
the interior and 60s along the coast. Temperatures will start to
trend downwards on Thursday, with highs dropping by 2 to 4 degrees,
before continuing to trend downwards Friday into Saturday as our
next system arrives. High temperatures Friday and Saturday will drop
into the 60s across the interior and upper 50s to low 60s along the
coast. Both the Euro and GFS show a weak cut-off upper level low
dropping into Central/Southern CA in the Wednesday-Thursday
timeframe which will bring decently moist PWATs back to the Bay Area
and Central Coast. Ensembles do not show much in the way of rain
from this weak upper level low, despite the increased moisture, with
drizzle along the coast and a return of low level clouds the most
likely result. Interestingly, the GFS shows this weak cut-off low
merging with a deeper upper level trough that is set to arrive
Friday into next weekend. This system does look to bring light rain
(similar in totals to this weekend`s system) and breezy to locally
gusty winds across the region Saturday into Sunday. The more
impactful component of next weekend`s system is likely to be the
breezy to gusty winds with initial ensemble guidance suggesting
gusts around 40 mph may be possible across the region. There does
appear to be some low level support, with a strong 850 mb jet
setting up along coastal portions of our CWA Saturday into Sunday
and a strong 500 mb jet just offshore. We will get a better idea
about both peak winds and rainfall totals associated with this
system as we get closer to next weekend, so stay tuned!

&&

.AVIATION...
(18Z TAFS)
Issued at 1103 AM PDT Sun Apr 27 2025

Impacts of upper low moving to our east is still impacting the
terminals and airspace with extensive low clouds over the region
this morning with bases roughly 1500-2500 feet. Radar showing
lingering showers from Santa Clara Valley southward through
Monterey county with KMRY the most likely to hold onto lingering
showers or drizzle through early afternoon. Expect gradual
clearing and lifting of cloud bases after 21z this afternoon with
light nw winds. Enough lingering moisture and cyclonic flow for
low clouds to stay in place overnight with higher confidence for
skies clearing with VFR conditions beyond 18z Monday.

Vicinity of SFO...Improving conditions after 21z with cigs mixing
and lifting before returning overnight through Monday morning.
Higher confidence for clearing skies and a return of VFR after 18z
Monday.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Lingering showers and drizzle through
early afternoon. High confidence for MVFR cigs to return overnight
through Monday morning with VFR conditions likely after 18z Monday.

&&

.MARINE...
(Today through Friday)
Issued at 904 AM PDT Sun Apr 27 2025

Northwest winds will be gusty due to a high pressure system
building over the offshore waters through early week, winds will
also result in hazardous seas across the outer coastal waters.
From mid to late week surface high pressure will gradually weaken
while an upper  level trough will move in from the northwest. By
late week another upper level trough from the northwest will
approach the coastal  waters and bays.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 9 PM PDT this evening for Mry Bay.

     Small Craft Advisory until 3 AM PDT Monday for Pt Arena to Pt
     Reyes 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm.

     Small Craft Advisory from 3 PM to 9 PM PDT Monday for Pt Arena
     to Pt Reyes 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm.

     Small Craft Advisory until 9 PM PDT this evening for Pigeon Pt
     to Pt Pinos 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

     Small Craft Advisory until 9 PM PDT Monday for Pigeon Pt to Pt
     Pinos 10-60 NM-Pt Arena to Pt Reyes 10-60 NM.

&&

$$

SHORT TERM...Kennedy
LONG TERM....Kennedy
AVIATION...RW
MARINE...RW

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